The main objectives of this study fall into two general areas: first, to provide a theoretical background and methodology for the analysis of the relationship among language, ideology, and power; and second, to apply the methodology to a specific set of texts, namely, English textbooks that are used in North and South Korea, identify the major ideology in the English textbooks of North and South Korea, and thus establish a relationship between the use of language and the manifestation of ideology and power in the two respective countries.The theoretical background of this study is found in the approaches to (critical) sociolinguistics in which the framework of analysis takes into consideration factors such as the context of situation, context of culture, and functionality of language. Thus it is found that a linguistic approach is needed to describe and explain the manners in which language is used in particular contexts in order to create specific ideologies that serve to sustain asymmetrical power relations in a given society.In developing a methodology for the analysis of language, ideology, and power, I adopted the suggestions given by Thompson (1984, 1987) that emphasize socio-historical, textual, and interpretive analyses. I further divide the textual analysis procedure into three components--micro, macro and linguistic--that examine the topical, thematic, propositional content, manifestations of ideology, and linguistic devices used in the text.By applying such methodology to the analysis of two sets of English language textbooks used in North and South Korea, this study identifies major manifestations of ideology in the two Koreas that serve to naturalize specific power relations (that may be either positive or negative) among the members of each society. The positive power relations promote a sense of equality and personal satisfaction for the majority of the people in the society while the negative power relations allow certain individuals, specific institutions, or special languages and cultures to exploit others by claiming their interests at the expense of others.The results of this study also reveal several linguistic methods utilized in the English language textbook that performs the function of maintaining specific power relationships among different groups of people within the respective countries. Thus the conclusion of this study shows that there is a strong relationship among English language education, manifestation of ideology and power structures in the two Koreas. This conclusion also suggest a strong possibility that similar relationships may exist in other countries as well.Some suggestions are given in the concluding chapter of this study that may help to bring critical language awareness to the language planners and textbook writers in the two Koreas.